CVE-2026-48689
FastNetMon Community Edition up to version 1.2.9 contains a critical off‑by‑one heap overflow that can be triggered by malicious network traffic. The flaw allows an attacker to write past the end of a buffer, potentially leading to arbitrary code execution. It affects BGP, NetFlow, sFlow, and IPFIX processing.
No official fix yet. If none appears within 45 days of first tracking, this entry is removed automatically.
Who is affected
FastNetMon Community Edition (pavel-odintsov fastnetmon) versions up to 1.2.9, used by network monitoring and traffic analysis systems.
Real-world impact
An attacker can send crafted NetFlow, sFlow, IPFIX, or BGP packets to a vulnerable FastNetMon instance, causing a heap overflow that could let them execute arbitrary code on the host.
Why this severity
The CVSS score of 9.8 reflects the vulnerability’s high impact: it requires no user interaction, can be triggered remotely over the network, and gives an attacker full control over the system.
What to do about it
- ›Avoid sending untrusted NetFlow, sFlow, IPFIX, or BGP traffic to the FastNetMon instance until a patch is released.
- ›Consider upgrading to a newer FastNetMon version if one is available that addresses the issue.
No official fix or mitigation is documented in the sources yet. Monitor the vendor advisory and apply the patch as soon as it is released.
No fix documented in sources
Timeline
- May 26, 2026 · May 26, 2026PublishedDisclosed and added to the National Vulnerability Database.
- Jul 24, 2026 · 11d agoAdvisory updatedThe NVD record was last revised.
How it’s attacked
References & advisories
- github.com/pavel-odintsov/fastnetmonproduct
- github.com/pavel-odintsov/fastnetmon/b…product
- lorikeetsecurity.com/blog/fastnetmon-cve-2026-48…exploitthird party advisory